﻿using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        private string firstnumber = "";
        private string action = "";
        public Form1()
        {
            InitializeComponent();
        }

        private void label1_Click(object sender, EventArgs e)
        {

        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            textBox1.Text += "1"; 
        }

        private void button2_Click(object sender, EventArgs e)
        {
            textBox1.Text += "2";
        }

        private void button3_Click(object sender, EventArgs e)
        {
            textBox1.Text += "3";
        }

        private void button4_Click(object sender, EventArgs e)
        {
            textBox1.Text += "4";
        }

        private void button5_Click(object sender, EventArgs e)
        {
            textBox1.Text += "5";
        }

        private void button6_Click(object sender, EventArgs e)
        {
            textBox1.Text += "6";
        }

        private void button7_Click(object sender, EventArgs e)
        {
            textBox1.Text += "7";
        }

        private void button8_Click(object sender, EventArgs e)
        {
            textBox1.Text += "8";
        }

        private void button9_Click(object sender, EventArgs e)
        {
            textBox1.Text += "9";
        }

        private void button0_Click(object sender, EventArgs e)
        {
            textBox1.Text += "0";
        }

        private void buttonPlus_Click(object sender, EventArgs e)
        {
            firstnumber = textBox1.Text;
            action = "+";
            textBox1.Text = "";
        }
        private void buttonMinus_Click(object sender, EventArgs e)
        {
            firstnumber = textBox1.Text;
            action = "-";
            textBox1.Text = "";
        }
        private void buttonUmn_Click(object sender, EventArgs e)
        {
            firstnumber = textBox1.Text;
            action = "*";
            textBox1.Text = "";
        }
        private void buttonDel_Click(object sender, EventArgs e)
        {
            firstnumber = textBox1.Text;
            action = "/";
            textBox1.Text = "";
        }
        private void buttonR_Click(object sender, EventArgs e)
        {
            int number = Convert.ToInt32 (textBox1.Text);
            int firstnumber1 = Convert.ToInt32(firstnumber);
            if (action == "+")
            {
                int summ1 = firstnumber1 + number;
                string summ = Convert.ToString(summ1);
                textBox1.Text = summ;
            }
            else if (action == "-")
            {
                int summ1 = firstnumber1 - number;
                string summ = Convert.ToString(summ1);
                textBox1.Text = summ;
            }
            else if (action == "*")
            {
                int summ1 = firstnumber1 * number;
                string summ = Convert.ToString(summ1);
                textBox1.Text = summ;
            }
            else if (action == "/")
            {
                int summ1 = firstnumber1 / number;
                string summ = Convert.ToString(summ1);
                textBox1.Text = summ;
            }
        }
    }
}
